This invention relates in general to equipment for handling sheet metal and, more particularly, to a machine for positioning empty skids in a stacking machine so that sheet metal panels can accumulate on such skids.
Metal sheet, particularly sheet steel, finds widespread use in manufactured products of many types, among which are housings for a variety of equipment including household appliances and cabinets of one sort or another. The metal sheet comes in large coils produced at rolling mills. In order to render the coiled metal sheet suitable for press work, the metal sheet must be withdrawn from the coil and cut into panels of sizes appropriate for the press work. This normally requires advancing the metal sheet into a shear and severing it transversely into panels, which fall from the shear one after the other. Often the metal sheet is much too wide for the panels required during the press work. In that event, the metal sheet is passed through a slitter which divides it into strips that then pass into the shear where each stroke of the shear blade produces multiple panels—as many as there are strips. The panels drop into a stacking machine where they accumulate in stacks, and when the stacks reach a predetermined number of panels, they are discharged, providing space for more stacks to form.
Each stack weighs far too much for a single individual to lift. To facilitate handling, skids, which are basically small pallets, are placed in the stacking machine where the panels accumulate, and indeed the stacks form on the skids. Each skid is slightly smaller, at least in width than the panels which accumulate on it, and this holds particularly true where the panels are cut from multiple strips that emerge from a slitter.
In this regard, the skids must not project laterally beyond the strips, for if they do they will interfere with dividers that lie along the sides of the strips to insure that the panels cut from the strips drop uniformly and accumulate with the margins of the stacked panels in registration. The stacking machine elevates the skids into the spaces between or along these dividers to receive the initial panels sheared from the strips, and if the skids are positioned improperly, they will interfere with the dividers and damage them. Thus, the operator of the stacking machine must manually position the skids to insure that they clear the dividers before the stacking machine elevates the skids. To be sure, a machine exists which pushes skids onto a stacking machine from one of its sides, and this machine can properly position a single pallet for receiving only a single panel with each stroke of the shear. Such a machine will also push multiple skids onto a stacking machine, each for receiving a different panel cut from a strip that emerges from a slitter. But the skids must be separated in the stacking machine before the machine elevates the skids, and this requires that the operator to reach into the machine and manually position the skids. The effort is taxing and time consuming.